drivers/power/twl4030_charger.c - kernel/bruno - Git at Google

 /*
  * TWL4030/TPS65950 BCI (Battery Charger Interface) driver
  *
  * Copyright (C) 2010 Gražvydas Ignotas <notasas@gmail.com>
  *
  * based on twl4030_bci_battery.c by TI
  * Copyright (C) 2008 Texas Instruments, Inc.
  *
  * This program is free software; you can redistribute it and/or modify
  * it under the terms of the GNU General Public License as published by
  * the Free Software Foundation; either version 2 of the License, or
  * (at your option) any later version.
  */

 #include <linux/init.h>
 #include <linux/module.h>
 #include <linux/slab.h>
 #include <linux/platform_device.h>
 #include <linux/interrupt.h>
 #include <linux/i2c/twl.h>
 #include <linux/power_supply.h>
 #include <linux/notifier.h>
 #include <linux/usb/otg.h>

 #define TWL4030_BCIMSTATEC	0x02
 #define TWL4030_BCIICHG		0x08
 #define TWL4030_BCIVAC		0x0a
 #define TWL4030_BCIVBUS		0x0c
 #define TWL4030_BCIMFSTS4	0x10
 #define TWL4030_BCICTL1		0x23

 #define TWL4030_BCIAUTOWEN	BIT(5)
 #define TWL4030_CONFIG_DONE	BIT(4)
 #define TWL4030_BCIAUTOUSB	BIT(1)
 #define TWL4030_BCIAUTOAC	BIT(0)
 #define TWL4030_CGAIN		BIT(5)
 #define TWL4030_USBFASTMCHG	BIT(2)
 #define TWL4030_STS_VBUS	BIT(7)
 #define TWL4030_STS_USB_ID	BIT(2)

 /* BCI interrupts */
 #define TWL4030_WOVF		BIT(0) /* Watchdog overflow */
 #define TWL4030_TMOVF		BIT(1) /* Timer overflow */
 #define TWL4030_ICHGHIGH	BIT(2) /* Battery charge current high */
 #define TWL4030_ICHGLOW		BIT(3) /* Battery cc. low / FSM state change */
 #define TWL4030_ICHGEOC		BIT(4) /* Battery current end-of-charge */
 #define TWL4030_TBATOR2		BIT(5) /* Battery temperature out of range 2 */
 #define TWL4030_TBATOR1		BIT(6) /* Battery temperature out of range 1 */
 #define TWL4030_BATSTS		BIT(7) /* Battery status */

 #define TWL4030_VBATLVL		BIT(0) /* VBAT level */
 #define TWL4030_VBATOV		BIT(1) /* VBAT overvoltage */
 #define TWL4030_VBUSOV		BIT(2) /* VBUS overvoltage */
 #define TWL4030_ACCHGOV		BIT(3) /* Ac charger overvoltage */

 #define TWL4030_MSTATEC_USB		BIT(4)
 #define TWL4030_MSTATEC_AC		BIT(5)
 #define TWL4030_MSTATEC_MASK		0x0f
 #define TWL4030_MSTATEC_QUICK1		0x02
 #define TWL4030_MSTATEC_QUICK7		0x07
 #define TWL4030_MSTATEC_COMPLETE1	0x0b
 #define TWL4030_MSTATEC_COMPLETE4	0x0e

 static bool allow_usb;
 module_param(allow_usb, bool, 1);
 MODULE_PARM_DESC(allow_usb, "Allow USB charge drawing default current");

 struct twl4030_bci {
 	struct device		*dev;
 	struct power_supply	ac;
 	struct power_supply	usb;
 	struct otg_transceiver	*transceiver;
 	struct notifier_block	otg_nb;
 	int			irq_chg;
 	int			irq_bci;
 };

 /*
  * clear and set bits on an given register on a given module
  */
 static int twl4030_clear_set(u8 mod_no, u8 clear, u8 set, u8 reg)
 {
 	u8 val = 0;
 	int ret;

 	ret = twl_i2c_read_u8(mod_no, &val, reg);
 	if (ret)
 		return ret;

 	val &= ~clear;
 	val |= set;

 	return twl_i2c_write_u8(mod_no, val, reg);
 }

 static int twl4030_bci_read(u8 reg, u8 *val)
 {
 	return twl_i2c_read_u8(TWL4030_MODULE_MAIN_CHARGE, val, reg);
 }

 static int twl4030_clear_set_boot_bci(u8 clear, u8 set)
 {
 	return twl4030_clear_set(TWL4030_MODULE_PM_MASTER, 0,
 			TWL4030_CONFIG_DONE | TWL4030_BCIAUTOWEN | set,
 			TWL4030_PM_MASTER_BOOT_BCI);
 }

 static int twl4030bci_read_adc_val(u8 reg)
 {
 	int ret, temp;
 	u8 val;

 	/* read MSB */
 	ret = twl4030_bci_read(reg + 1, &val);
 	if (ret)
 		return ret;

 	temp = (int)(val & 0x03) << 8;

 	/* read LSB */
 	ret = twl4030_bci_read(reg, &val);
 	if (ret)
 		return ret;

 	return temp | val;
 }

 /*
  * Check if VBUS power is present
  */
 static int twl4030_bci_have_vbus(struct twl4030_bci *bci)
 {
 	int ret;
 	u8 hwsts;

 	ret = twl_i2c_read_u8(TWL4030_MODULE_PM_MASTER, &hwsts,
 			      TWL4030_PM_MASTER_STS_HW_CONDITIONS);
 	if (ret < 0)
 		return 0;

 	dev_dbg(bci->dev, "check_vbus: HW_CONDITIONS %02x\n", hwsts);

 	/* in case we also have STS_USB_ID, VBUS is driven by TWL itself */
 	if ((hwsts & TWL4030_STS_VBUS) && !(hwsts & TWL4030_STS_USB_ID))
 		return 1;

 	return 0;
 }

 /*
  * Enable/Disable USB Charge funtionality.
  */
 static int twl4030_charger_enable_usb(struct twl4030_bci *bci, bool enable)
 {
 	int ret;

 	if (enable) {
 		/* Check for USB charger conneted */
 		if (!twl4030_bci_have_vbus(bci))
 			return -ENODEV;

 		/*
 		 * Until we can find out what current the device can provide,
 		 * require a module param to enable USB charging.
 		 */
 		if (!allow_usb) {
 			dev_warn(bci->dev, "USB charging is disabled.\n");
 			return -EACCES;
 		}

 		/* forcing the field BCIAUTOUSB (BOOT_BCI[1]) to 1 */
 		ret = twl4030_clear_set_boot_bci(0, TWL4030_BCIAUTOUSB);
 		if (ret < 0)
 			return ret;

 		/* forcing USBFASTMCHG(BCIMFSTS4[2]) to 1 */
 		ret = twl4030_clear_set(TWL4030_MODULE_MAIN_CHARGE, 0,
 			TWL4030_USBFASTMCHG, TWL4030_BCIMFSTS4);
 	} else {
 		ret = twl4030_clear_set_boot_bci(TWL4030_BCIAUTOUSB, 0);
 	}

 	return ret;
 }

 /*
  * Enable/Disable AC Charge funtionality.
  */
 static int twl4030_charger_enable_ac(bool enable)
 {
 	int ret;

 	if (enable)
 		ret = twl4030_clear_set_boot_bci(0, TWL4030_BCIAUTOAC);
 	else
 		ret = twl4030_clear_set_boot_bci(TWL4030_BCIAUTOAC, 0);

 	return ret;
 }

 /*
  * TWL4030 CHG_PRES (AC charger presence) events
  */
 static irqreturn_t twl4030_charger_interrupt(int irq, void *arg)
 {
 	struct twl4030_bci *bci = arg;

 	dev_dbg(bci->dev, "CHG_PRES irq\n");
 	power_supply_changed(&bci->ac);
 	power_supply_changed(&bci->usb);

 	return IRQ_HANDLED;
 }

 /*
  * TWL4030 BCI monitoring events
  */
 static irqreturn_t twl4030_bci_interrupt(int irq, void *arg)
 {
 	struct twl4030_bci *bci = arg;
 	u8 irqs1, irqs2;
 	int ret;

 	ret = twl_i2c_read_u8(TWL4030_MODULE_INTERRUPTS, &irqs1,
 			      TWL4030_INTERRUPTS_BCIISR1A);
 	if (ret < 0)
 		return IRQ_HANDLED;

 	ret = twl_i2c_read_u8(TWL4030_MODULE_INTERRUPTS, &irqs2,
 			      TWL4030_INTERRUPTS_BCIISR2A);
 	if (ret < 0)
 		return IRQ_HANDLED;

 	dev_dbg(bci->dev, "BCI irq %02x %02x\n", irqs2, irqs1);

 	if (irqs1 & (TWL4030_ICHGLOW | TWL4030_ICHGEOC)) {
 		/* charger state change, inform the core */
 		power_supply_changed(&bci->ac);
 		power_supply_changed(&bci->usb);
 	}

 	/* various monitoring events, for now we just log them here */
 	if (irqs1 & (TWL4030_TBATOR2 | TWL4030_TBATOR1))
 		dev_warn(bci->dev, "battery temperature out of range\n");

 	if (irqs1 & TWL4030_BATSTS)
 		dev_crit(bci->dev, "battery disconnected\n");

 	if (irqs2 & TWL4030_VBATOV)
 		dev_crit(bci->dev, "VBAT overvoltage\n");

 	if (irqs2 & TWL4030_VBUSOV)
 		dev_crit(bci->dev, "VBUS overvoltage\n");

 	if (irqs2 & TWL4030_ACCHGOV)
 		dev_crit(bci->dev, "Ac charger overvoltage\n");

 	return IRQ_HANDLED;
 }

 static int twl4030_bci_usb_ncb(struct notifier_block *nb, unsigned long val,
 			       void *priv)
 {
 	struct twl4030_bci *bci = container_of(nb, struct twl4030_bci, otg_nb);

 	dev_dbg(bci->dev, "OTG notify %lu\n", val);

 	switch (val) {
 	case USB_EVENT_VBUS:
 	case USB_EVENT_CHARGER:
 		twl4030_charger_enable_usb(bci, true);
 		break;
 	case USB_EVENT_NONE:
 		twl4030_charger_enable_usb(bci, false);
 		break;
 	}

 	return NOTIFY_OK;
 }

 /*
  * TI provided formulas:
  * CGAIN == 0: ICHG = (BCIICHG * 1.7) / (2^10 - 1) - 0.85
  * CGAIN == 1: ICHG = (BCIICHG * 3.4) / (2^10 - 1) - 1.7
  * Here we use integer approximation of:
  * CGAIN == 0: val * 1.6618 - 0.85
  * CGAIN == 1: (val * 1.6618 - 0.85) * 2
  */
 static int twl4030_charger_get_current(void)
 {
 	int curr;
 	int ret;
 	u8 bcictl1;

 	curr = twl4030bci_read_adc_val(TWL4030_BCIICHG);
 	if (curr < 0)
 		return curr;

 	ret = twl4030_bci_read(TWL4030_BCICTL1, &bcictl1);
 	if (ret)
 		return ret;

 	ret = (curr * 16618 - 850 * 10000) / 10;
 	if (bcictl1 & TWL4030_CGAIN)
 		ret *= 2;

 	return ret;
 }

 /*
  * Returns the main charge FSM state
  * Or < 0 on failure.
  */
 static int twl4030bci_state(struct twl4030_bci *bci)
 {
 	int ret;
 	u8 state;

 	ret = twl4030_bci_read(TWL4030_BCIMSTATEC, &state);
 	if (ret) {
 		pr_err("twl4030_bci: error reading BCIMSTATEC\n");
 		return ret;
 	}

 	dev_dbg(bci->dev, "state: %02x\n", state);

 	return state;
 }

 static int twl4030_bci_state_to_status(int state)
 {
 	state &= TWL4030_MSTATEC_MASK;
 	if (TWL4030_MSTATEC_QUICK1 <= state && state <= TWL4030_MSTATEC_QUICK7)
 		return POWER_SUPPLY_STATUS_CHARGING;
 	else if (TWL4030_MSTATEC_COMPLETE1 <= state &&
 					state <= TWL4030_MSTATEC_COMPLETE4)
 		return POWER_SUPPLY_STATUS_FULL;
 	else
 		return POWER_SUPPLY_STATUS_NOT_CHARGING;
 }

 static int twl4030_bci_get_property(struct power_supply *psy,
 				    enum power_supply_property psp,
 				    union power_supply_propval *val)
 {
 	struct twl4030_bci *bci = dev_get_drvdata(psy->dev->parent);
 	int is_charging;
 	int state;
 	int ret;

 	state = twl4030bci_state(bci);
 	if (state < 0)
 		return state;

 	if (psy->type == POWER_SUPPLY_TYPE_USB)
 		is_charging = state & TWL4030_MSTATEC_USB;
 	else
 		is_charging = state & TWL4030_MSTATEC_AC;

 	switch (psp) {
 	case POWER_SUPPLY_PROP_STATUS:
 		if (is_charging)
 			val->intval = twl4030_bci_state_to_status(state);
 		else
 			val->intval = POWER_SUPPLY_STATUS_NOT_CHARGING;
 		break;
 	case POWER_SUPPLY_PROP_VOLTAGE_NOW:
 		/* charging must be active for meaningful result */
 		if (!is_charging)
 			return -ENODATA;
 		if (psy->type == POWER_SUPPLY_TYPE_USB) {
 			ret = twl4030bci_read_adc_val(TWL4030_BCIVBUS);
 			if (ret < 0)
 				return ret;
 			/* BCIVBUS uses ADCIN8, 7/1023 V/step */
 			val->intval = ret * 6843;
 		} else {
 			ret = twl4030bci_read_adc_val(TWL4030_BCIVAC);
 			if (ret < 0)
 				return ret;
 			/* BCIVAC uses ADCIN11, 10/1023 V/step */
 			val->intval = ret * 9775;
 		}
 		break;
 	case POWER_SUPPLY_PROP_CURRENT_NOW:
 		if (!is_charging)
 			return -ENODATA;
 		/* current measurement is shared between AC and USB */
 		ret = twl4030_charger_get_current();
 		if (ret < 0)
 			return ret;
 		val->intval = ret;
 		break;
 	case POWER_SUPPLY_PROP_ONLINE:
 		val->intval = is_charging &&
 			twl4030_bci_state_to_status(state) !=
 				POWER_SUPPLY_STATUS_NOT_CHARGING;
 		break;
 	default:
 		return -EINVAL;
 	}

 	return 0;
 }

 static enum power_supply_property twl4030_charger_props[] = {
 	POWER_SUPPLY_PROP_STATUS,
 	POWER_SUPPLY_PROP_ONLINE,
 	POWER_SUPPLY_PROP_VOLTAGE_NOW,
 	POWER_SUPPLY_PROP_CURRENT_NOW,
 };

 static int __init twl4030_bci_probe(struct platform_device *pdev)
 {
 	struct twl4030_bci *bci;
 	int ret;
 	int reg;

 	bci = kzalloc(sizeof(*bci), GFP_KERNEL);
 	if (bci == NULL)
 		return -ENOMEM;

 	bci->dev = &pdev->dev;
 	bci->irq_chg = platform_get_irq(pdev, 0);
 	bci->irq_bci = platform_get_irq(pdev, 1);

 	platform_set_drvdata(pdev, bci);

 	bci->ac.name = "twl4030_ac";
 	bci->ac.type = POWER_SUPPLY_TYPE_MAINS;
 	bci->ac.properties = twl4030_charger_props;
 	bci->ac.num_properties = ARRAY_SIZE(twl4030_charger_props);
 	bci->ac.get_property = twl4030_bci_get_property;

 	ret = power_supply_register(&pdev->dev, &bci->ac);
 	if (ret) {
 		dev_err(&pdev->dev, "failed to register ac: %d\n", ret);
 		goto fail_register_ac;
 	}

 	bci->usb.name = "twl4030_usb";
 	bci->usb.type = POWER_SUPPLY_TYPE_USB;
 	bci->usb.properties = twl4030_charger_props;
 	bci->usb.num_properties = ARRAY_SIZE(twl4030_charger_props);
 	bci->usb.get_property = twl4030_bci_get_property;

 	ret = power_supply_register(&pdev->dev, &bci->usb);
 	if (ret) {
 		dev_err(&pdev->dev, "failed to register usb: %d\n", ret);
 		goto fail_register_usb;
 	}

 	ret = request_threaded_irq(bci->irq_chg, NULL,
 			twl4030_charger_interrupt, 0, pdev->name, bci);
 	if (ret < 0) {
 		dev_err(&pdev->dev, "could not request irq %d, status %d\n",
 			bci->irq_chg, ret);
 		goto fail_chg_irq;
 	}

 	ret = request_threaded_irq(bci->irq_bci, NULL,
 			twl4030_bci_interrupt, 0, pdev->name, bci);
 	if (ret < 0) {
 		dev_err(&pdev->dev, "could not request irq %d, status %d\n",
 			bci->irq_bci, ret);
 		goto fail_bci_irq;
 	}

 	bci->transceiver = otg_get_transceiver();
 	if (bci->transceiver != NULL) {
 		bci->otg_nb.notifier_call = twl4030_bci_usb_ncb;
 		otg_register_notifier(bci->transceiver, &bci->otg_nb);
 	}

 	/* Enable interrupts now. */
 	reg = ~(TWL4030_ICHGLOW | TWL4030_ICHGEOC | TWL4030_TBATOR2 |
 		TWL4030_TBATOR1 | TWL4030_BATSTS);
 	ret = twl_i2c_write_u8(TWL4030_MODULE_INTERRUPTS, reg,
 			       TWL4030_INTERRUPTS_BCIIMR1A);
 	if (ret < 0) {
 		dev_err(&pdev->dev, "failed to unmask interrupts: %d\n", ret);
 		goto fail_unmask_interrupts;
 	}

 	reg = ~(TWL4030_VBATOV | TWL4030_VBUSOV | TWL4030_ACCHGOV);
 	ret = twl_i2c_write_u8(TWL4030_MODULE_INTERRUPTS, reg,
 			       TWL4030_INTERRUPTS_BCIIMR2A);
 	if (ret < 0)
 		dev_warn(&pdev->dev, "failed to unmask interrupts: %d\n", ret);

 	twl4030_charger_enable_ac(true);
 	twl4030_charger_enable_usb(bci, true);

 	return 0;

 fail_unmask_interrupts:
 	if (bci->transceiver != NULL) {
 		otg_unregister_notifier(bci->transceiver, &bci->otg_nb);
 		otg_put_transceiver(bci->transceiver);
 	}
 	free_irq(bci->irq_bci, bci);
 fail_bci_irq:
 	free_irq(bci->irq_chg, bci);
 fail_chg_irq:
 	power_supply_unregister(&bci->usb);
 fail_register_usb:
 	power_supply_unregister(&bci->ac);
 fail_register_ac:
 	platform_set_drvdata(pdev, NULL);
 	kfree(bci);

 	return ret;
 }

 static int __exit twl4030_bci_remove(struct platform_device *pdev)
 {
 	struct twl4030_bci *bci = platform_get_drvdata(pdev);

 	twl4030_charger_enable_ac(false);
 	twl4030_charger_enable_usb(bci, false);

 	/* mask interrupts */
 	twl_i2c_write_u8(TWL4030_MODULE_INTERRUPTS, 0xff,
 			 TWL4030_INTERRUPTS_BCIIMR1A);
 	twl_i2c_write_u8(TWL4030_MODULE_INTERRUPTS, 0xff,
 			 TWL4030_INTERRUPTS_BCIIMR2A);

 	if (bci->transceiver != NULL) {
 		otg_unregister_notifier(bci->transceiver, &bci->otg_nb);
 		otg_put_transceiver(bci->transceiver);
 	}
 	free_irq(bci->irq_bci, bci);
 	free_irq(bci->irq_chg, bci);
 	power_supply_unregister(&bci->usb);
 	power_supply_unregister(&bci->ac);
 	platform_set_drvdata(pdev, NULL);
 	kfree(bci);

 	return 0;
 }

 static struct platform_driver twl4030_bci_driver = {
 	.driver	= {
 		.name	= "twl4030_bci",
 		.owner	= THIS_MODULE,
 	},
 	.remove	= __exit_p(twl4030_bci_remove),
 };

 static int __init twl4030_bci_init(void)
 {
 	return platform_driver_probe(&twl4030_bci_driver, twl4030_bci_probe);
 }
 module_init(twl4030_bci_init);

 static void __exit twl4030_bci_exit(void)
 {
 	platform_driver_unregister(&twl4030_bci_driver);
 }
 module_exit(twl4030_bci_exit);

 MODULE_AUTHOR("Gražydas Ignotas");
 MODULE_DESCRIPTION("TWL4030 Battery Charger Interface driver");
 MODULE_LICENSE("GPL");
 MODULE_ALIAS("platform:twl4030_bci");
	/*
	* TWL4030/TPS65950 BCI (Battery Charger Interface) driver
	*
	* Copyright (C) 2010 Gražvydas Ignotas <notasas@gmail.com>
	*
	* based on twl4030_bci_battery.c by TI
	* Copyright (C) 2008 Texas Instruments, Inc.
	*
	* This program is free software; you can redistribute it and/or modify
	* it under the terms of the GNU General Public License as published by
	* the Free Software Foundation; either version 2 of the License, or
	* (at your option) any later version.
	*/

	#include <linux/init.h>
	#include <linux/module.h>
	#include <linux/slab.h>
	#include <linux/platform_device.h>
	#include <linux/interrupt.h>
	#include <linux/i2c/twl.h>
	#include <linux/power_supply.h>
	#include <linux/notifier.h>
	#include <linux/usb/otg.h>

	#define TWL4030_BCIMSTATEC 0x02
	#define TWL4030_BCIICHG 0x08
	#define TWL4030_BCIVAC 0x0a
	#define TWL4030_BCIVBUS 0x0c
	#define TWL4030_BCIMFSTS4 0x10
	#define TWL4030_BCICTL1 0x23

	#define TWL4030_BCIAUTOWEN BIT(5)
	#define TWL4030_CONFIG_DONE BIT(4)
	#define TWL4030_BCIAUTOUSB BIT(1)
	#define TWL4030_BCIAUTOAC BIT(0)
	#define TWL4030_CGAIN BIT(5)
	#define TWL4030_USBFASTMCHG BIT(2)
	#define TWL4030_STS_VBUS BIT(7)
	#define TWL4030_STS_USB_ID BIT(2)

	/* BCI interrupts */
	#define TWL4030_WOVF BIT(0) /* Watchdog overflow */
	#define TWL4030_TMOVF BIT(1) /* Timer overflow */
	#define TWL4030_ICHGHIGH BIT(2) /* Battery charge current high */
	#define TWL4030_ICHGLOW BIT(3) /* Battery cc. low / FSM state change */
	#define TWL4030_ICHGEOC BIT(4) /* Battery current end-of-charge */
	#define TWL4030_TBATOR2 BIT(5) /* Battery temperature out of range 2 */
	#define TWL4030_TBATOR1 BIT(6) /* Battery temperature out of range 1 */
	#define TWL4030_BATSTS BIT(7) /* Battery status */

	#define TWL4030_VBATLVL BIT(0) /* VBAT level */
	#define TWL4030_VBATOV BIT(1) /* VBAT overvoltage */
	#define TWL4030_VBUSOV BIT(2) /* VBUS overvoltage */
	#define TWL4030_ACCHGOV BIT(3) /* Ac charger overvoltage */

	#define TWL4030_MSTATEC_USB BIT(4)
	#define TWL4030_MSTATEC_AC BIT(5)
	#define TWL4030_MSTATEC_MASK 0x0f
	#define TWL4030_MSTATEC_QUICK1 0x02
	#define TWL4030_MSTATEC_QUICK7 0x07
	#define TWL4030_MSTATEC_COMPLETE1 0x0b
	#define TWL4030_MSTATEC_COMPLETE4 0x0e

	static bool allow_usb;
	module_param(allow_usb, bool, 1);
	MODULE_PARM_DESC(allow_usb, "Allow USB charge drawing default current");

	struct twl4030_bci {
	struct device *dev;
	struct power_supply ac;
	struct power_supply usb;
	struct otg_transceiver *transceiver;
	struct notifier_block otg_nb;
	int irq_chg;
	int irq_bci;
	};

	/*
	* clear and set bits on an given register on a given module
	*/
	static int twl4030_clear_set(u8 mod_no, u8 clear, u8 set, u8 reg)
	{
	u8 val = 0;
	int ret;

	ret = twl_i2c_read_u8(mod_no, &val, reg);
	if (ret)
	return ret;

	val &= ~clear;
	val \|= set;

	return twl_i2c_write_u8(mod_no, val, reg);
	}

	static int twl4030_bci_read(u8 reg, u8 *val)
	{
	return twl_i2c_read_u8(TWL4030_MODULE_MAIN_CHARGE, val, reg);
	}

	static int twl4030_clear_set_boot_bci(u8 clear, u8 set)
	{
	return twl4030_clear_set(TWL4030_MODULE_PM_MASTER, 0,
	TWL4030_CONFIG_DONE \| TWL4030_BCIAUTOWEN \| set,
	TWL4030_PM_MASTER_BOOT_BCI);
	}

	static int twl4030bci_read_adc_val(u8 reg)
	{
	int ret, temp;
	u8 val;

	/* read MSB */
	ret = twl4030_bci_read(reg + 1, &val);
	if (ret)
	return ret;

	temp = (int)(val & 0x03) << 8;

	/* read LSB */
	ret = twl4030_bci_read(reg, &val);
	if (ret)
	return ret;

	return temp \| val;
	}

	/*
	* Check if VBUS power is present
	*/
	static int twl4030_bci_have_vbus(struct twl4030_bci *bci)
	{
	int ret;
	u8 hwsts;

	ret = twl_i2c_read_u8(TWL4030_MODULE_PM_MASTER, &hwsts,
	TWL4030_PM_MASTER_STS_HW_CONDITIONS);
	if (ret < 0)
	return 0;

	dev_dbg(bci->dev, "check_vbus: HW_CONDITIONS %02x\n", hwsts);

	/* in case we also have STS_USB_ID, VBUS is driven by TWL itself */
	if ((hwsts & TWL4030_STS_VBUS) && !(hwsts & TWL4030_STS_USB_ID))
	return 1;

	return 0;
	}

	/*
	* Enable/Disable USB Charge funtionality.
	*/
	static int twl4030_charger_enable_usb(struct twl4030_bci *bci, bool enable)
	{
	int ret;

	if (enable) {
	/* Check for USB charger conneted */
	if (!twl4030_bci_have_vbus(bci))
	return -ENODEV;

	/*
	* Until we can find out what current the device can provide,
	* require a module param to enable USB charging.
	*/
	if (!allow_usb) {
	dev_warn(bci->dev, "USB charging is disabled.\n");
	return -EACCES;
	}

	/* forcing the field BCIAUTOUSB (BOOT_BCI[1]) to 1 */
	ret = twl4030_clear_set_boot_bci(0, TWL4030_BCIAUTOUSB);
	if (ret < 0)
	return ret;

	/* forcing USBFASTMCHG(BCIMFSTS4[2]) to 1 */
	ret = twl4030_clear_set(TWL4030_MODULE_MAIN_CHARGE, 0,
	TWL4030_USBFASTMCHG, TWL4030_BCIMFSTS4);
	} else {
	ret = twl4030_clear_set_boot_bci(TWL4030_BCIAUTOUSB, 0);
	}

	return ret;
	}

	/*
	* Enable/Disable AC Charge funtionality.
	*/
	static int twl4030_charger_enable_ac(bool enable)
	{
	int ret;

	if (enable)
	ret = twl4030_clear_set_boot_bci(0, TWL4030_BCIAUTOAC);
	else
	ret = twl4030_clear_set_boot_bci(TWL4030_BCIAUTOAC, 0);

	return ret;
	}

	/*
	* TWL4030 CHG_PRES (AC charger presence) events
	*/
	static irqreturn_t twl4030_charger_interrupt(int irq, void *arg)
	{
	struct twl4030_bci *bci = arg;

	dev_dbg(bci->dev, "CHG_PRES irq\n");
	power_supply_changed(&bci->ac);
	power_supply_changed(&bci->usb);

	return IRQ_HANDLED;
	}

	/*
	* TWL4030 BCI monitoring events
	*/
	static irqreturn_t twl4030_bci_interrupt(int irq, void *arg)
	{
	struct twl4030_bci *bci = arg;
	u8 irqs1, irqs2;
	int ret;

	ret = twl_i2c_read_u8(TWL4030_MODULE_INTERRUPTS, &irqs1,
	TWL4030_INTERRUPTS_BCIISR1A);
	if (ret < 0)
	return IRQ_HANDLED;

	ret = twl_i2c_read_u8(TWL4030_MODULE_INTERRUPTS, &irqs2,
	TWL4030_INTERRUPTS_BCIISR2A);
	if (ret < 0)
	return IRQ_HANDLED;

	dev_dbg(bci->dev, "BCI irq %02x %02x\n", irqs2, irqs1);

	if (irqs1 & (TWL4030_ICHGLOW \| TWL4030_ICHGEOC)) {
	/* charger state change, inform the core */
	power_supply_changed(&bci->ac);
	power_supply_changed(&bci->usb);
	}

	/* various monitoring events, for now we just log them here */
	if (irqs1 & (TWL4030_TBATOR2 \| TWL4030_TBATOR1))
	dev_warn(bci->dev, "battery temperature out of range\n");

	if (irqs1 & TWL4030_BATSTS)
	dev_crit(bci->dev, "battery disconnected\n");

	if (irqs2 & TWL4030_VBATOV)
	dev_crit(bci->dev, "VBAT overvoltage\n");

	if (irqs2 & TWL4030_VBUSOV)
	dev_crit(bci->dev, "VBUS overvoltage\n");

	if (irqs2 & TWL4030_ACCHGOV)
	dev_crit(bci->dev, "Ac charger overvoltage\n");

	return IRQ_HANDLED;
	}

	static int twl4030_bci_usb_ncb(struct notifier_block *nb, unsigned long val,
	void *priv)
	{
	struct twl4030_bci *bci = container_of(nb, struct twl4030_bci, otg_nb);

	dev_dbg(bci->dev, "OTG notify %lu\n", val);

	switch (val) {
	case USB_EVENT_VBUS:
	case USB_EVENT_CHARGER:
	twl4030_charger_enable_usb(bci, true);
	break;
	case USB_EVENT_NONE:
	twl4030_charger_enable_usb(bci, false);
	break;
	}

	return NOTIFY_OK;
	}

	/*
	* TI provided formulas:
	* CGAIN == 0: ICHG = (BCIICHG * 1.7) / (2^10 - 1) - 0.85
	* CGAIN == 1: ICHG = (BCIICHG * 3.4) / (2^10 - 1) - 1.7
	* Here we use integer approximation of:
	* CGAIN == 0: val * 1.6618 - 0.85
	* CGAIN == 1: (val * 1.6618 - 0.85) * 2
	*/
	static int twl4030_charger_get_current(void)
	{
	int curr;
	int ret;
	u8 bcictl1;

	curr = twl4030bci_read_adc_val(TWL4030_BCIICHG);
	if (curr < 0)
	return curr;

	ret = twl4030_bci_read(TWL4030_BCICTL1, &bcictl1);
	if (ret)
	return ret;

	ret = (curr * 16618 - 850 * 10000) / 10;
	if (bcictl1 & TWL4030_CGAIN)
	ret *= 2;

	return ret;
	}

	/*
	* Returns the main charge FSM state
	* Or < 0 on failure.
	*/
	static int twl4030bci_state(struct twl4030_bci *bci)
	{
	int ret;
	u8 state;

	ret = twl4030_bci_read(TWL4030_BCIMSTATEC, &state);
	if (ret) {
	pr_err("twl4030_bci: error reading BCIMSTATEC\n");
	return ret;
	}

	dev_dbg(bci->dev, "state: %02x\n", state);

	return state;
	}

	static int twl4030_bci_state_to_status(int state)
	{
	state &= TWL4030_MSTATEC_MASK;
	if (TWL4030_MSTATEC_QUICK1 <= state && state <= TWL4030_MSTATEC_QUICK7)
	return POWER_SUPPLY_STATUS_CHARGING;
	else if (TWL4030_MSTATEC_COMPLETE1 <= state &&
	state <= TWL4030_MSTATEC_COMPLETE4)
	return POWER_SUPPLY_STATUS_FULL;
	else
	return POWER_SUPPLY_STATUS_NOT_CHARGING;
	}

	static int twl4030_bci_get_property(struct power_supply *psy,
	enum power_supply_property psp,
	union power_supply_propval *val)
	{
	struct twl4030_bci *bci = dev_get_drvdata(psy->dev->parent);
	int is_charging;
	int state;
	int ret;

	state = twl4030bci_state(bci);
	if (state < 0)
	return state;

	if (psy->type == POWER_SUPPLY_TYPE_USB)
	is_charging = state & TWL4030_MSTATEC_USB;
	else
	is_charging = state & TWL4030_MSTATEC_AC;

	switch (psp) {
	case POWER_SUPPLY_PROP_STATUS:
	if (is_charging)
	val->intval = twl4030_bci_state_to_status(state);
	else
	val->intval = POWER_SUPPLY_STATUS_NOT_CHARGING;
	break;
	case POWER_SUPPLY_PROP_VOLTAGE_NOW:
	/* charging must be active for meaningful result */
	if (!is_charging)
	return -ENODATA;
	if (psy->type == POWER_SUPPLY_TYPE_USB) {
	ret = twl4030bci_read_adc_val(TWL4030_BCIVBUS);
	if (ret < 0)
	return ret;
	/* BCIVBUS uses ADCIN8, 7/1023 V/step */
	val->intval = ret * 6843;
	} else {
	ret = twl4030bci_read_adc_val(TWL4030_BCIVAC);
	if (ret < 0)
	return ret;
	/* BCIVAC uses ADCIN11, 10/1023 V/step */
	val->intval = ret * 9775;
	}
	break;
	case POWER_SUPPLY_PROP_CURRENT_NOW:
	if (!is_charging)
	return -ENODATA;
	/* current measurement is shared between AC and USB */
	ret = twl4030_charger_get_current();
	if (ret < 0)
	return ret;
	val->intval = ret;
	break;
	case POWER_SUPPLY_PROP_ONLINE:
	val->intval = is_charging &&
	twl4030_bci_state_to_status(state) !=
	POWER_SUPPLY_STATUS_NOT_CHARGING;
	break;
	default:
	return -EINVAL;
	}

	return 0;
	}

	static enum power_supply_property twl4030_charger_props[] = {
	POWER_SUPPLY_PROP_STATUS,
	POWER_SUPPLY_PROP_ONLINE,
	POWER_SUPPLY_PROP_VOLTAGE_NOW,
	POWER_SUPPLY_PROP_CURRENT_NOW,
	};

	static int __init twl4030_bci_probe(struct platform_device *pdev)
	{
	struct twl4030_bci *bci;
	int ret;
	int reg;

	bci = kzalloc(sizeof(*bci), GFP_KERNEL);
	if (bci == NULL)
	return -ENOMEM;

	bci->dev = &pdev->dev;
	bci->irq_chg = platform_get_irq(pdev, 0);
	bci->irq_bci = platform_get_irq(pdev, 1);

	platform_set_drvdata(pdev, bci);

	bci->ac.name = "twl4030_ac";
	bci->ac.type = POWER_SUPPLY_TYPE_MAINS;
	bci->ac.properties = twl4030_charger_props;
	bci->ac.num_properties = ARRAY_SIZE(twl4030_charger_props);
	bci->ac.get_property = twl4030_bci_get_property;

	ret = power_supply_register(&pdev->dev, &bci->ac);
	if (ret) {
	dev_err(&pdev->dev, "failed to register ac: %d\n", ret);
	goto fail_register_ac;
	}

	bci->usb.name = "twl4030_usb";
	bci->usb.type = POWER_SUPPLY_TYPE_USB;
	bci->usb.properties = twl4030_charger_props;
	bci->usb.num_properties = ARRAY_SIZE(twl4030_charger_props);
	bci->usb.get_property = twl4030_bci_get_property;

	ret = power_supply_register(&pdev->dev, &bci->usb);
	if (ret) {
	dev_err(&pdev->dev, "failed to register usb: %d\n", ret);
	goto fail_register_usb;
	}

	ret = request_threaded_irq(bci->irq_chg, NULL,
	twl4030_charger_interrupt, 0, pdev->name, bci);
	if (ret < 0) {
	dev_err(&pdev->dev, "could not request irq %d, status %d\n",
	bci->irq_chg, ret);
	goto fail_chg_irq;
	}

	ret = request_threaded_irq(bci->irq_bci, NULL,
	twl4030_bci_interrupt, 0, pdev->name, bci);
	if (ret < 0) {
	dev_err(&pdev->dev, "could not request irq %d, status %d\n",
	bci->irq_bci, ret);
	goto fail_bci_irq;
	}

	bci->transceiver = otg_get_transceiver();
	if (bci->transceiver != NULL) {
	bci->otg_nb.notifier_call = twl4030_bci_usb_ncb;
	otg_register_notifier(bci->transceiver, &bci->otg_nb);
	}

	/* Enable interrupts now. */
	reg = ~(TWL4030_ICHGLOW \| TWL4030_ICHGEOC \| TWL4030_TBATOR2 \|
	TWL4030_TBATOR1 \| TWL4030_BATSTS);
	ret = twl_i2c_write_u8(TWL4030_MODULE_INTERRUPTS, reg,
	TWL4030_INTERRUPTS_BCIIMR1A);
	if (ret < 0) {
	dev_err(&pdev->dev, "failed to unmask interrupts: %d\n", ret);
	goto fail_unmask_interrupts;
	}

	reg = ~(TWL4030_VBATOV \| TWL4030_VBUSOV \| TWL4030_ACCHGOV);
	ret = twl_i2c_write_u8(TWL4030_MODULE_INTERRUPTS, reg,
	TWL4030_INTERRUPTS_BCIIMR2A);
	if (ret < 0)
	dev_warn(&pdev->dev, "failed to unmask interrupts: %d\n", ret);

	twl4030_charger_enable_ac(true);
	twl4030_charger_enable_usb(bci, true);

	return 0;

	fail_unmask_interrupts:
	if (bci->transceiver != NULL) {
	otg_unregister_notifier(bci->transceiver, &bci->otg_nb);
	otg_put_transceiver(bci->transceiver);
	}
	free_irq(bci->irq_bci, bci);
	fail_bci_irq:
	free_irq(bci->irq_chg, bci);
	fail_chg_irq:
	power_supply_unregister(&bci->usb);
	fail_register_usb:
	power_supply_unregister(&bci->ac);
	fail_register_ac:
	platform_set_drvdata(pdev, NULL);
	kfree(bci);

	return ret;
	}

	static int __exit twl4030_bci_remove(struct platform_device *pdev)
	{
	struct twl4030_bci *bci = platform_get_drvdata(pdev);

	twl4030_charger_enable_ac(false);
	twl4030_charger_enable_usb(bci, false);

	/* mask interrupts */
	twl_i2c_write_u8(TWL4030_MODULE_INTERRUPTS, 0xff,
	TWL4030_INTERRUPTS_BCIIMR1A);
	twl_i2c_write_u8(TWL4030_MODULE_INTERRUPTS, 0xff,
	TWL4030_INTERRUPTS_BCIIMR2A);

	if (bci->transceiver != NULL) {
	otg_unregister_notifier(bci->transceiver, &bci->otg_nb);
	otg_put_transceiver(bci->transceiver);
	}
	free_irq(bci->irq_bci, bci);
	free_irq(bci->irq_chg, bci);
	power_supply_unregister(&bci->usb);
	power_supply_unregister(&bci->ac);
	platform_set_drvdata(pdev, NULL);
	kfree(bci);

	return 0;
	}

	static struct platform_driver twl4030_bci_driver = {
	.driver = {
	.name = "twl4030_bci",
	.owner = THIS_MODULE,
	},
	.remove = __exit_p(twl4030_bci_remove),
	};

	static int __init twl4030_bci_init(void)
	{
	return platform_driver_probe(&twl4030_bci_driver, twl4030_bci_probe);
	}
	module_init(twl4030_bci_init);

	static void __exit twl4030_bci_exit(void)
	{
	platform_driver_unregister(&twl4030_bci_driver);
	}
	module_exit(twl4030_bci_exit);

	MODULE_AUTHOR("Gražydas Ignotas");
	MODULE_DESCRIPTION("TWL4030 Battery Charger Interface driver");
	MODULE_LICENSE("GPL");
	MODULE_ALIAS("platform:twl4030_bci");